Circuit breaker



June 16, 1931. E. H. w. ULLRICH CIRCUIT BREAKER Filed April 30, 1928 2 Sheets-Sheet l avwenkoz EMIL H. W. ULLRICF yizz'a 2i02vzqya My W Hll Hmw June 16, 1931. E. H. w. ULLRICH 1,810,861

CIRCUIT BREAKER Filed April 30, 1928 2 Sheets-Sheet 2 MIN avwenboz EMIL H. W. ULLRICH 2y izis' aiiar/zjys f UM WW I Patented June 16, 1931 UNITED STATES PATENT OFFICE EMIL W. ULLRICH, OF NEW YORK, N. Y., ASSIGNOR TO THE BRYANT ELECTRIC COM- PANY, OF

BRIDGEBORT, CONNECTICUT, A. CORPORATION OF CONNECTICUT ciaoui'r BREAKER Application filed April 30,

in which the circuit .may be opened and closed at will by hand, and which is also automatically opened on overload.

My invention also includes the thought of manually resetting the mechanism, after automatic operation, by means of the leyer which is employed for the manual actuation of the mechanism. Various features of novelty, construction and operation will be pointed out in the following-specification, or as shown in the accompanying drawings in which- Fig. 1 is a secti n through a circuit-breaker in which my invention is embodied in one form and showing position;

Fig. 2 is a similar view showing the parts in open-circuit position following manual operation of the operating lever;

Fig. 3 is a section on the line 3-3, Fig. 1; Fi 4 is a view showing the open-circuit position of the breaker following automatic operation;

Fig. 5 is a rear view, with the partsin' the position shown in Fig. 1; and Figs. 6 and 7 are views of certain details; The present mechanism will be recognized in its specific form as a development of the circuit breaker which forms the subject of Patent No. 1,656,851, dated January 17, 1928. One of the features of the mechanism disclosed in said patent, is the fact that on the automatic trip following overload, the manually operated actuator is shifted only partially from its circuit-closing position toward the position which it assumes in open-circuit position when manuall operated. This has the advantage of a ording a graphic indication of the automatic opening of the circuit. It has the disadvantage that in order to reset the mechanism and close the circuit again, two movements are necessary, viz., one which shifts the operating member to the full open-circuit position which it occupies when manually operated,

the parts in closed circuit followed by a return of the operating mem- 1928. Serial No. 274,036.

motions heretofore necessary in order to reset the mechanism and close the circuit, these operations being now performed by the single movement of the operating member to circuit-closing position.

If an indication of the automatic opening of the circuit be desired, this is readily afforded by a member independent of the op erating lever.

Referring to the accompanying drawings, I have indicated at 24 a wire connection from which current is led to one leg of the U-shaped thermostatic element 48 the current returning through the other leg thereof and passing by strap 54 to one of the fixed contacts 26 of the circuit breaker. The other fixed contact 29 (Fig. 3) is in turn electrically connected with a wire terminal 25 at the other side of the line.

The circuit is closed between the contacts 26 and 29 by an oscillatin switch block 30 carried by but insulated rom the rock lever 31. The free ends of the rock lever 31 are shaped to pivot in the angle of the double V-frame 33. One leg of this V-frame is pivoted at 34 in the fixed standard 35. The other leg of the V-frame 33 is provided with a foot piece 32 which projects into a notch 42 of the trip lever 43 pivoted at 44 to the base plate of the standard 35. The free end of the trip lever 43 is provided with a nose 45 which in the normal position of the parts is engaged with the insulated trip flange 46 at the closed end of the thermostatic U-bar 48. This engagement of the trip lever by the thermostat is constant during normal current conditions, and the opening or closing of the switch must be accomplished during this period solely by manual operation of the circuit breaker.

The manual operating member here employed for this purpose comprises a lever 19 forkedat its inner end to straddle the head and foot pieces of the fixed standard 35 having a rocking bearing on outwardl offset lugs 36 on the respective head an foot pieces of the standard 35. The throw of the lever 19 to circuit-closing position ma be limited by the stop lugs 38 on the stan ard 35. The manual throw of the lever to openand x i the pivoted V-frame 33.

circuit position is limited by stop lugs 50 on The OI. erating connectionbetween the switch lever 31 and operating lever 19 is established by the pull spring .39 connectedto themespective cross bars of these members, 31 and 19, the relation of the parts being such that when the operating lever 19 is manually swung toward open-circuit position, the stress of the spring is carried over center with respect to the pivotal axis of the switch lever 31, Fig. 2. The parts so far described are substantially similar to those shown and described in the prior patent hereinabove referred to, and in this description I have for the most part used the same reference numerals.

The automatic operation of the circuit breaker which follows the warping of the thermostatic element out of engagement with the nose 45 of the trip lever 43, is occasioned by a relatively heavy coiled spring 51 anchored at 52 to the base, and at its other end to the lug 53 at the end of arm 55 of a plate 56, which is pivoted at 57 substantially in register with the pivot 36 of the operating lever. A lug 61 upstanding from this plate engages one margin of the operating lever 19 and may cooperate with or take the place of lugs 38 to form a stop for the lever 19 in cirmuit-closing position. In order to hold the plate '56 normally in fixed position, I provide a detent 59 pivoted at 64 and adapted at its opposite end to engage the lug at the adjacent margin of the member 56. A spring 63 normally holds the detent 59 in position. to engage the lug 60, thus sustaining the member 56 in fixed position against the constant stresses of the spring 51. When the thermostatic bar 48 is warped by current overload until the engagement of ofi'set 46 with the nose 45 of the trip lever 43 is broken, the V-frame 33 isrthereupon freed for displacement under the stress of the spring 39. The effortof this switch spring 39 exerted through the switch lever 31 against the V-frame 33, tends constantly to press the foot piece -32 against the lower jaw of the notch 42 of the trip lever 43. Consequently, when the" detent engagement between the thermostat and trip lever is broken at 45-46, the effort of the spring 39 displaces the rocking V -frame 33 on its piv otal axis 34. The trip lever 43 is forced out wardly (Fig. 4) on.its pivot 44, while the V-frame 33 is rocked downwardly on its pivot 34. The rocking of the V-frame downwardly throws the lug 58 thereof into.

' engagement with the latch -59 and thus kicks the latter out of engagement with the stop lug 60 on the plate 56. The latter is now free to move under the stress of the heavy ';coil spring 51 tothe position shown in Fig.

4.Z ";Inasmuch as the lug 61 of the plate 56 engages the operating lever 19, the throw of the plate 56 under the stress of heavy spring frame 33 is not co-incident with the axis 57 ofthe plate 56, the engagement between the lug 60 on the plate 56, and the lug 58 of the V-frame, is 'a sliding engagement but is maintained during the swing of the plate 56 under the influence of spring 51 until the V-frame 33 is returned to substantially normal position. Therefore, while the switch lever 19 remains in open-circuit position, to which it has'been shifted by the plate 56, the return of the V-frame 33 to'its normal position through the engagement of lu s 58 and 60 respectively, simultaneously e ects the return of the trip lever 43 to its normal position by reason of the engagement of the footpiece 32 of the V-frame 33 in the open jaw 42. Consequently, when the heat has suiiiciently radiated from the legs of the thermostat bar to permit the latter to resume its normal position, the engagement of its lip 46 with the nose 45 of the trip lever 43, will thereby be rev-established on the ever, in addition to overcoming the stress of the'swltch spring 39 durlng this movement, it is necessary to overcome the resistance also of the coil spring 51 since the lug 61 of plate 56 is engaged by the lever 19, and the plate56 must be swung on its pivot 57 (Fig. 6) to reset position durin this stroke of the operating lever. When, iowever, the operating leverhas reached normal circuitclosing position, lug 60 on plate 56 is reengaged by the dog 59, -thus holding the plate 56 and its associated parts in fixed position (Fig. 6) until the next succeeding overload with the resultant kicking of the do 59 out of contact with the lug 58 of the V-f rame (Fig. 1).

It being my purpose to reset the V-frame 33in normal position at the end of the inovement of the plate 56, following thermostatic release, it is obvious that the position which the lever 19 assumes is the position to which it is shifted on the opening of the circuit breaker, either manually or automatically.

It is obvious that after automatic' operation of the circuit breaker, the'parts cannot be returned to normal position until the thermostat 48-has sufficiently cooled to restore its latchefi to position for cooperating with the nose 45 of the trip lever 43. This will be the more obvious when it is considered that the foot piece 32 of the V-frame 33 is engaged in the jaw 42. This is an added feature of safety, although of minor importance, since the immediate warping of the thermostat following return to closure position, would in case of overload, automatically release the mechanism.

It may also, be pointed out that it is impossible to hold the mechanism in circuitclosing position by maintaining the operating lever 19 manually against the pull of the spring 51 following the thermostatic release of the trip lever 43. The warping of the thermostatic element and the disengagement of its lip 46 from the nose 45 of the trip lever 43, permit the V-frame to rock under the stress of spring 39, as above pointed out. This movement is sufficient to throw the stress of the switch spring 39 across the axis of oscillation of the switch bar 31, with the result that even though the operating lever 19 be held positively in circuit-closing position, the circuit is opened by the throw of the switch block 30, following the rocking of the V-frame 33 and the consequent throw of the switch'iblojek" 30 in open-circuit position. a

It will be understood of course that the mechanism shown illustrates but an embodiment of the thoughts which underlie my invention, and that various modifications of structure may be made which still embody the characteristics which I claim as my invention.

I claim- 1. In an automatic circuit breaker, a spring-stressed operating lever manually movable between a single open circuit and a closed-circuit position, a spring-stressed element engaging the lever to move it to opencircuit position, a detent normally holding said element in fixed location enabling said lever to occupy either of its positions, and a thermostatically controlled means acting on overload to open the circuit independently of the said operating lever andto free said detent. 4 v

I 2. In an automatic circuit breaker, an operating lever manually movable between a single open circuit and a closed-circuit position, a spring stressing said operating lever,

a springstressed element engaging the leverto move "it to open-circuit position, a detent normally holding said element in fixed location, and a thermostatically controlled element actuated by the operating lever spring .for freeing said detent on overload.

'- 3, In a circuit breaker, a rocking frame, a fixed support for sa d rocklng frame, a switch lever pivoted on said rocking frame,

ing said frame normally and for releasing it on overload, and a spring-stressed i'nember serving to shift the operating lever to opencircuit position upon displacement of said frame.

4. In a circuit breaker, a rocking frame, a switch lever pivoted therein, a thermostatically controlled trip mechanism holding said rocking frame normally in fixed position, said frame being adapted to put said lever in open circuit position, a manually operated lever tothrow the switch lever to closedor open-circuit position, a member tending constantly to throw the operating lever to opencircuit position and to ,nio've said frame to its normal position engaging said trip, and a detent restraining said member against operation, together with thermostatically released means actuating said rocking frame and thereby effecting release of said detent, on overload.

5. In a circuit breaker, an oscillating frame, a switch lever pivoted therein, and a spring to thrust the lever against the frame,

in combination with an operating lever, a

member adapted to cooperate therewith to shift the operating lever to open-circuit position, thermostatically controlled means for maintaining the oscillating frame in fixed position, a detent for holding against movement the member for throwing the operating lever to open-circuit position, said oscillating frame upon escape from the thermostatically controlled member having a-movement in one direction under the influence of the switch spring to release the detent, and a restoring movement in theopposite direction on the throw of the oscillating lever to opencircuit position under the influence of said lever-operatingmeans when the latter are freed by the release of the detent.

6. In a circuit breaker, an oscillating switch lever, an oscillating frame in which it is supported, a spring to act upon the lever,

an operating lever having operative connection with the contact lever to shift the'latter to open-circuit position, a thermostatically controlled support for the rocking frame, normally maintaining the latter in fixed position, but permitting the same to rock in one direction under the stress of the-circuitclosing spring following release of the spring by operation ofthe thermostat on overload, in combination with detcnt-'controlled means released by said movement of the rocking frame, and simultaneously lever in open circuit throwiug the operating lever toopen-circuit position.

7. In a circuit breaker, an oscillating switch lever, an oscillating frame in which it is supported, a spring to act upon the lever, an operating lever having operative connection with the contact lever to shift the latter to open-circuit position, a ther- .mostatically controlled support for the rocking frame, normally maintaining the latter in fixed position but permitting the same to rock in one direction under the stress of the circuit-closing spring following release of the spring by operation of the thermostat on overload, in combination with detent-controlled means released by said movement of the rocking frame and simultaneously throwing the operating lever to open-circuit position, said operating lever being ineffective to return the contact lever to closed-circuit position until the return of the thermostatic element to normal position.

8. In a circuit breaker, an oscillating switch lever, an oscillating frame in which it is supported, a spring to act upon the lever, an operating lever having operative connection with the contact lever to shift the latter to open-circuit position, a thermostatically controlled support for the rocking frame, normally maintaining the latter in fixed position but permitting the same to rock in one direction under the stress of the circuit-closing spring following release of the spring by operation of the thermostat on overload, in combination with detentcontrolled means released by said movement of the rocking frame and simultaneously throwing the operating lever to open-circuit position, and a one-Way engagement between said operating lever and detent controlled device, whereby the return ofsaid lever to closed-circuit position re-establishes the mech thermostatic element has returned to normal position.

9. In a circuit breaker, a switch lever, an operating lever therefor manually shiftable to open and closed-circuit mally restrained means automatically released on overload for utting the switch lever in open circuit posltion independently of the operating lever, and a spring means, rendered operative by the action of said means in putting the switch lever in open circuit position, for restoring said means to its normal position and for shifting said operating lever to open circuit position.

10. In a circuit breaker, a switch lever, an operating lever therefor manually shiftable to open and closed-circuit positions,- a normally restrained means automatically released on overload for putting'said switch position independently of said operating lever, a spring stressed device tending when released to put said opanism in normal position only if the erating lever in open-circuit position and to restore said means to its normal position, a detent normally holding said spring device, said detent being released when said means puts the switch lever in open-circuit position and being reset by movement of said operating lever toward closed circuit position.

11. In a circuit breaker, a switchl'ever, an operating lever therefor manually shiftable to open and closed-circuit positions, a rocking frame for putting said switch lever in open-circuit position independently of said operating lever, a spring for moving said switch lever upon shifting of said operating lever and tending to put said frame in position to open the circuit, a latch normally holding said frame against the effort of said spring and a thermostatic trip for said latch, in combination with a spring stressed member acting when released to move said operating lever to open-circuit position and to reset said frame and latch ready for re-engagement by said trip, a detent normally holding said member free of said operating lever, said detent being released by said frame in its rocking and reset by said operating lever in its movement toward closed-circuit position.

In testimony whereof I have signed my name to this specification.

EMIL H. W. ULLRICH.

pos1t1ons, a nor- 

